This very short saga has ended, as Preet Bharara confirmed on Twitter and CNBC that he's been fired:
I did not resign. Moments ago I was fired. Being the US Attorney in SDNY will forever be the greatest honor of my professional life. — Preet Bharara (@PreetBharara) March 11, 2017
Why it matters: It's normal for an incoming administration to name their own U.S. attorneys, but Trump himself told Bharara that he would be free to keep his job. Clearly, something has changed.